CVE-2002-1816 in ATPhttpd
Summary
by MITRE
Off-by-one buffer overflow in the sock_gets function in sockhelp.c for ATPhttpd 0.4b and earlier allows remote attackers to execute arbitrary code via a long HTTP GET request.
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Analysis
by VulDB Data Team • 01/16/2025
The vulnerability identified as CVE-2002-1816 represents a critical buffer overflow flaw within the ATPhttpd web server software version 0.4b and earlier. This issue resides in the sock_gets function located within the sockhelp.c source file, demonstrating a classic off-by-one error that creates an exploitable condition for remote code execution. The vulnerability specifically manifests when processing HTTP GET requests, making it particularly dangerous in web server environments where such requests are constantly received and processed. The flaw arises from insufficient bounds checking during string operations, allowing attackers to manipulate input data in a manner that exceeds the allocated buffer space by precisely one byte.
The technical implementation of this vulnerability involves the sock_gets function failing to properly validate the length of incoming data before copying it into a fixed-size buffer. When an attacker crafts a malicious HTTP GET request containing an excessively long string, the function's inadequate boundary checking permits the overflow to occur. This off-by-one condition creates a scenario where the attacker can overwrite adjacent memory locations, potentially corrupting program execution flow and allowing arbitrary code execution. The vulnerability's remote exploitability means that attackers need only send a specially crafted request to the affected server without requiring local access or authentication credentials. This characteristic places the vulnerability at the intersection of network-based attacks and privilege escalation, as successful exploitation can grant full control over the affected system.
From an operational impact perspective, this vulnerability presents a severe threat to web server security and system integrity. The potential for remote code execution means that an attacker could gain complete control over the ATPhttpd server, potentially leading to data breaches, service disruption, or further network infiltration. The vulnerability affects versions 0.4b and earlier, indicating that organizations running these older versions face significant exposure risk, particularly in environments where patch management processes are delayed or incomplete. The nature of the flaw makes it particularly challenging to detect through standard network monitoring, as the malicious traffic may appear as normal HTTP GET requests until the overflow occurs. This characteristic also means that the vulnerability could remain undetected for extended periods, providing attackers with prolonged access to compromised systems.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term security posture improvements. The primary and most effective solution involves upgrading to ATPhttpd versions that contain patches addressing this specific buffer overflow issue. Organizations should also implement input validation measures to limit the length of HTTP GET requests and employ intrusion detection systems that can identify suspicious request patterns. Network segmentation and firewall rules can help reduce the attack surface by limiting direct access to vulnerable web servers. Additionally, implementing application-level firewalls and web application firewalls can provide an additional layer of protection by filtering malicious requests before they reach the vulnerable software components. The vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a clear example of how improper input handling can lead to critical security compromises. From an ATT&CK framework perspective, this vulnerability maps to techniques involving remote code execution through software vulnerabilities and can be leveraged for initial access and persistence within compromised environments. Organizations should also consider implementing comprehensive vulnerability management programs to identify and remediate similar issues across their entire software portfolio, as this vulnerability demonstrates the importance of regular security assessments and timely patch deployment.